Dan Boyle was recently reading about a fellow graybeard, the Panthers’ 43-year-old winger Jaromir Jagr, and the story helped explain something to him.

“I read an article on how Jagr was talking about how as you get older, the start of the season is always hard on him, and tougher to get going,” Boyle told The Post before Monday night’s 2-1 win over the Bruins at the Garden. “Maybe that was just the case for me — it just takes a little while for the engine to get going, so to speak. But I think the last couple months, I think I’ve been playing the way I know I can play.”

Boyle, 39, had found a way to become more steady and reliable, which is almost the exact opposite description of his first year and a half on the Rangers’ blue line. At least this season, he looks back to how he changed his preparation as part of the reason he has been able to at least somewhat turn things around.

“I just try to find things that will work,” Boyle said. “I was in the gym a lot at the beginning of the season, believe it or not. Probably was in there a little bit too much. You just try to find a routine that works. I’m in there still, but maybe not as much.

“It’s just about listening to your body and seeing what works and what doesn’t. If it works, you stick with it; if it doesn’t, you change it. I’m not really a superstitious guy where I’m sticking to something no matter. If things aren’t going well, find something that’s going to make it work. And when it does, I stick to it.”

The same can be said for the way coach Alain Vigneault has dealt with Boyle over the past few weeks. Because of injuries to right-side stalwarts Dan Girardi and Kevin Klein, there was quite a bit more responsibility heaped on Boyle. That was in stark contrast to the way the season started, as Vigneault scratched Boyle for six of the team’s first 24 games.

But since Girardi and Klein both returned on Dec. 28, Boyle has stayed in the lineup — while big-bodied 23-year-old rookie Dylan McIlrath remained a healthy scratch — and the veteran has continued to get important minutes. It helps that the team has turned around a 3-9-2 run with a 4-2-1 stretch over the previous seven games, including an emphatic 6-2 win over the Stars on Tuesday night and a big point against the NHL-leading Capitals on Saturday afternoon at the Garden.

“There is no doubt that in the last weeks, he’s been a dependable player defensively,” Vigneault said. “Everybody knows we brought Dan in because he’s got a lot of power-play experience.”

So Boyle has even found a new spot on the power play, atop the left circle where he has operated with savvy vision and a sharp one-timer to help that first unit become more dynamic. Although the man-advantage is 0-for-15 in the previous six games, it had been 8-for-33 in the preceding seven contests, getting it to an 18.8 percent success rate, good for 13th in the league.

And Boyle had two goals and seven assists — nine of his 14 overall points — on the man-advantage, showing that usefulness that helped convince the Rangers to sign him to a two-year, $9 million deal two summers ago.

“He was able to run power plays both in San Jose and Tampa, did a real good job,” Vigneault said. “So that experience and that background and feedback to our group is something that we’re looking for. I think his play here is like a lot of our players, it’s picking up. It’s getting better. And it’s at the right time because it’s very competitive.”

The Rangers were only three points clear of being out of playoff position, and they really couldn’t afford another slipup. Boyle is not as integral to the blue line as Girardi or Klein — or Ryan McDonagh and Marc Staal on the left, either — but it sure does help that he had been a steadying presence rather than a detriment.

“I think I got off to a tough start, that’s the bottom line,” Boyle said. “But the last couple months, I’ve felt a lot better. I’m doing what I can to help out.”